12 research outputs found
Investigations of Pressurized Lu–N–H Materials by Using the Hybrid Functional
Recently, Lu–N–H materials were reported
to have
room-temperature superconductivity, the Hubbard U correction on Lu’s f-electrons is necessary,
and a constant U = 5.5 eV was applied to different
Lu–N–H configurations. The following simulations demonstrate
that different U values lead to different superconducting
transition temperatures. Here, the structural and electronic Lu–N–H
properties at high pressure (0–10 GPa) are systematically investigated
based on the hybrid functional. We show that different Lu–N–H
configurations should possess different U values
varying from 6.4 to 7.4 eV. Furthermore, at pressures ranging from
0 to 1 GPa, the f and d band centers
of N-doped LuH3 show oscillation or even plateau, and the
band gap of insulators also shows a platform, consistent with the
pressure range for room-temperature superconductivity in Lu–N–H.
Our work provides insight into understanding Lu–N–H
materials and other hydrogen-rich superconductors based on rare-earth
elements
NMR Chemical Shifts of <sup>15</sup>N‑Bearing Graphene
The <sup>15</sup>N NMR chemical shifts
of possible nitrogen-containing moieties at edges and defects of graphene
are investigated by using the first-principles method. Our computational
results show that pyridine-like and graphite-like N can be rather
easily identified using the <sup>15</sup>N NMR technique, in agreement
with experiment. On the other hand, pyridinium-like <sup>15</sup>N
is hardly distinguished from the pyrrole-like one using the NMR, because
these <sup>15</sup>N nuclei give nearly overlapping signals. However,
our simulations suggest that <sup>1</sup>H NMR is useful to discriminate
between them; the NMR chemical shifts of <sup>1</sup>H directly bonded
with pyridinium-like and pyrrole-like N along the armchair edge are
estimated to be 0.8 and 10.1 ppm, respectively, while the corresponding
chemical shift for pyridinium-like N along the zigzag edge is located
between them. The <sup>15</sup>N NMR signals for various moieties
at edges we considered are found to be similar to the corresponding
ones at defects except for pyridine-like nitrogens. Conversely, the <sup>15</sup>N NMR chemical shifts are altered sensitively by the degree
of aggregation of pyridine-like <sup>15</sup>N atoms both along armchair
edges and at defect sites. Interestingly, the graphite-like <sup>15</sup>N doped along zigzag edges, which was attributed in our previous
work to an active configuration for oxygen reduction reaction at the
cathode of fuel cells, is identifiable via NMR irrespective of the
details of samples such as edge terminations, dopant distributions,
and graphene sizes
G-T nucleotide distribution on 1st codon position of all four sets of ORFs.
<p>(a) G-T distribution of 4835 positive and 3515 negative samples in training sets. (b) G-T distribution for 1256 predicted genes and 488 rejected spurious ORFs and all 1744 ORFs are those originally labeled as dubious or uncharacterized by the SGD annotation.</p
List of misclassified genes in 10-fold cross-validation.<sup>*</sup>
*<p>All the 15 misclassified ORFs (with an average length of 296.6 nucleotides) are small ORFs, which are usually difficult to identify.</p
Performance for all the 63 groups of measurements in cross-validation.<sup>*</sup>
*<p>Six measurements are represented as following: 1/mono-nucleotide frequencies, 2/di-nucleotide frequencies, 3/mono-codon composition, 4/di-codon composition, 5/mono-amino acid usages, 6/di-amino acid usages.</p>a<p>The boldface letter indicates the group with highest accuracy among the 63 combinations.</p
Interaction Mechanism of Re(VII) with Zirconium Dioxide Nanoparticles Archored onto Reduced Graphene Oxides
Zirconium
oxide archored onto reduced graphene oxides (ZrO<sub>2</sub>@rGO)
was fabricated via a hydrothermal method and used for
ReÂ(VII) removal from aqueous solutions. Scanning electron microscopy,
Fourier transferred infrared spectroscopy, X-ray diffraction, thermogravimetric
analysis, and X-ray photoelectron spectroscopy were used to characterize
the as-prepared ZrO<sub>2</sub>@rGO. The results indicated that ZrO<sub>2</sub> was successfully decorated on rGO. The maximum sorption capacity
of ZrO<sub>2</sub>@rGO toward ReÂ(VII) was 43.55 mg/g. ZrO<sub>2</sub>@rGO exhibited enhanced sorption capacity for ReÂ(VII) in comparison
with bare ZrO<sub>2</sub> or rGO. The sorption kinetics could be described
by the pseudo-second-order equation. The sorption process of ReÂ(VII)
on ZrO<sub>2</sub>@rGO was endothermic and spontaneous. X-ray photoelectron
spectroscopy indicated the formation of an ionic bond of Zr–O
with ReÂ(VII). According to the density functional theory calculations,
O<sub>Re</sub>–Zr bonds on the surface of the monoclinic ZrO<sub>2</sub> plane (m-ZrO<sub>2</sub>) (111) plane and tetragonal ZrO<sub>2</sub> (t-ZrO<sub>2</sub>) (111) plane were formed when ReÂ(VII)
sorbs. The sorption energy of ReÂ(VII) onto the t-ZrO<sub>2</sub> (111)
plane was 3.87 eV, being higher than that of ReÂ(VII) onto m-ZrO<sub>2</sub> (1.26 eV)
MOESM1 of Statistically controlled identification of differentially expressed genes in one-to-one cell line comparisons of the CMAP database for drug repositioning
Additional file 1: Table S1. Overlap of DEGs detected by SAM (FDR < 20%) and OneComp
MOESM5 of Statistically controlled identification of differentially expressed genes in one-to-one cell line comparisons of the CMAP database for drug repositioning
Additional file 5: Table S5. The result of GO gene ontology enrichment of the 298 reversed associated with phenformin (P < 5%)
L'Auto-vélo : automobilisme, cyclisme, athlétisme, yachting, aérostation, escrime, hippisme / dir. Henri Desgranges
01 février 19411941/02/01 (A41,N14612)
High-Pressure Synthesis of CeOCl Crystals and Investigation of Their Photoluminescence and Compressibility Properties
The
well-crystallized mixed anions compound cerium oxychloride
(CeOCl) was successfully synthesized by a high-pressure solid-state
metathesis reaction. The photoluminescence experiment shows that the
CeOCl, with a band gap of ∼3.05 eV, has good violet-blue emission
properties. And first-principles calculations of the band structures
show that CeOCl is an indirect (direct) band gap semiconductor for
the spin-up (spin-down) branch. This suggests that the CeOCl can be
expected to be a semiconductor material. In addition, <i>in</i> <i>situ</i> high-pressure angle-dispersive X-ray diffraction
experiment reveals that the bulk modulus of CeOCl is 52.8(8) GPa,
which is close to our first-principles calculations, giving that <i>B</i><sub>0</sub> = 47.6(5) GPa